What term is used to describe the deep furrows or fissures in the cortex?

The term used to describe the deep furrows or fissures in the cortex is sulci. Sulci are the grooves found on the surface of the brain that separate the raised areas called gyri. These structures are critical in increasing the surface area of the brain, which allows for a greater amount of neuronal connections and enhanced cognitive function. The presence and pattern of sulci can vary between individuals and play a significant role in identifying different areas of the brain, as various regions responsible for different functions are located between these grooves. Understanding the structure of sulci is essential for studying brain anatomy and physiology, as they are critical landmarks for neuroscientific research and clinical practice.